Sequenced phase panelboard



June 1, 1965 J. A. HERRMANN ETAL 3,187,228

SEQUENCED PHASE PANELBOARD 9 Sheets-Sheet 1 Filed June 5, 1963 June 1,19 5 J. A. HERRMANN ETAL 3,187,228

SEQUENCED PHASE PANELBOARD 9 Sheets-Sheet 2 Filed June 5, 1963 Junel,1965 J. A. HERRMANN ETAL 3,187,228

SEQUENCED PHASE PANELBOARD 9 Sheets-Sheet 3 Filed June 5, 1965 June 1,1965 J. A. HERRMANN ETAL 3,187,228 SEQUENCED PHASE PANELBOARD Filed June5, 1963 9 Sheets-Sheet 4 INVENTORS k/a/sw A- yawn m June 1, 1965 J. A.HERRMANN ETAL SEQUENCED PHASE PANELBOARD Filed June 5, 1965 9Sheets-Sheet 5 June 1, 1965 J. A. HERRMANN ETAL 3,187,228

SEQUENGED PHASE PANELBOARD 9 Sheets-Sheet 6 Filed June 5, 1963 J. A.HERRMANN ETAL 3,187,228 SEQUENCED PHASE PANELBOARD 7 June 1, 1965 9Sheets-Sheet 7 Filed Jung 5. 1963 'QmNfil N mNE mmmm June 1, 1965 J.HERRMANN ETAL SEQUENCE-D PHASE PANELBOARD 9 Sheets-Sheet 8 Filed June 5,1963 IN VEN ab N RWY mULHl June 1, 1965 J. A. HERRMANN ETAL 3,137,228

SEQUENCED PHASE PANELBOARD Filed June 5, 1963 9 Sheets-Sheet 9 w w jIE1. 5A-

BY 1 W600 Z 7117/2 breaker. Briefly, the device of the instant UnitedStates Patent ice 3 SEQUENCED FHASE PANEIJEUARD John A. Herrniann andElwood T. Plats, Grosse Pointe This invention relates to panelboards ingeneral and more particularly to a multi-phase panelboard for lightindustrial applications.

The Farnsworth et al. pending application Serial No. 806,959, filedApril 16, 1959, now abandoned, discloses a panelboard for mountingcircuit breakers of the type illustrated in the R. W. Thomas, US. PatentNo. 2,938,- 983, issued May 31, 1960, entitled Circuit Breaker Latch.The circuit breaker illustrated in the aforesaid patent is provided withline and load'terminals which project from the same side of the circuitbreaker housing with this side of the housing in front of the panelboardmounting plate. Mounting hooks are provided for the circuit breaker withthese hooks extending from a housing wall which is opposite the Wallcontaining the terminals. Heretofore panelboards for mounting suchcircuit breakers consisted of a central mounting rib with single busbars parallel to the rib on opposite sides thereof as illustrated in theaforesaid copending application 806,959.

I-Ieretofore, no practical arrangement has been proposed for providingmore than one bus bar on the same side of the mounting rib. Accordingly,panelboards for this type of circuit breaker were limited to three Wiresingle phase units. Because of this the application of the circuitbreakers was limited. That is, in many installations three phaseelectrical energy is present and no practical three phase panelboard hadbeen provided by the prior art for circuit breakers of this type.

The instant invention provides a novel and practical panelboardconstruction for the utilization of circuit breakers in which both theline and load terminals are mounted to the housing wall which isopposite the wall carrying, the mechanical mounting means for thecircuit invention provides a U-shaped insulator positioned with acircuit breaker mounting rib midway between the arms of the U andextending parallel thereto. Three U-shaped bus bars are substantiallyenclosed by the insulator and are so constructed that circuit breakerconnecting portions thereof extend'outside the confines of theinsulator.

The circuit breaker connecting portons of the bus bars are arranged inrows extending parallel to the mounting rib with these connectingportions being positioned in a single plane at the forward surface ofthe insulator. The bus bars are so constructed that the circuit breakerconnecting portions are sequenced. That is, a connecting portion of onebus bar is positioned between a connecting portion of a second bus barand a connecting portion or" the third bus bar. This is in compliancewith requirements of electrical codes and also facilitates the mountingof multi-phase circuit breakers of the type illustrated in the pendingapplication, Serial No. 285,681, filed Iune 5., 1963, entitledMulti-Phase Circuit Breaker, with E. T. Platz as inventor and assignedto the assignee of the instant invention.

Accordingly, a primary object of this invention is to provide a novelconstruction for a three phase panelboard to receive circuit breakerswhose contacts are mounted to a housing wall which is opposite thehousing wall having the mechanical mounting means for the circuitbreaker.

Another object is to provide a panelboard of this type which is ofsubstantially the same width as three wire singie phase panelboards forcircuit breakers of this type.

3,187,228 Fat-tented June 1, 1965 Still another object is to provide athree phase panelboard of this type in which the phasing is sequenced.

A further object is to provide a construction in which panelboardcurrent capacity may be increased without changing the width proportionsof the bus bar structure.

A still further object is to provide a construction of this type for anadapter so that a breaker may be used as a general purpose device or asa main breaker for a panelboard.

These as well as further objects of this invention shall become readilyapparent after reading the following description of the accompanyingdrawings in which:

FIGURE 1 is a plan view of a panel-board constructed in accordance withthe teachings of the instant invention.

FIGURE 2 is a side elevation of the panelboard of FIGURE 1.

FIGURE 3 is a cross-section taken through line 33 of FIGURE 1 looking inthe direction of arrows 3-3.

FIGURE 4 is a cross-section taken through line 4-4 of FIGURE I lookingin the direction of arrows 4-4.

FIGURE 5 is a partial end view of the panelboard looking in thedirection of arrows 55 of FIGURE 1.

FIGURE 6 is a plan view of the main insulator for the panelboard ofFIGURE 1.

FIGURE 6A is a bottom view of the insulator of FIGURE 6.

FIGURE 7 is a side elevation of the insulator.

FIGURE 8 is a partial cross-section of the insulator of FIGURE 6 takenthrough line S8 of FIGURE 6 looking in the direction of arrows 8-8.

FIGURE 9 is a plan View of the inner bus bar of the panelboard of FIGURE1 prior to installation of this bus bar.

FIGURE 9A is a side elevation of the inner bus bar of FIGURE 9.

FIGURE 10 is the outer bus bar for the panelboard of FIGURE 1 prior toinstallation of this bus bar.

FIGURE 10A is a side elevation of the bus bar of FIGURE 10.

FIGURE 11 is a plan view of the middle bus bar for the panel board ofFIGURE 1.

FIGURE 11A is a side elevation of the bus bar of FIGURE 11.

FIGURE 11B is a partial end view of the bus bar of FIGURE 11.

FIGURE 12 is a plan view of a bus bar which is secured to the bus bar ofFIGURE 11 for higher rated panelboards.

FIGURE 12A is a side elevation of the bus bar of FIGURE 12.

FIGURE 13 is an exploded perspective showing the relationships betweenthe bus bars of FIGURES 9 through 12.

FIGURE 14 is a plan view of a second embodiment of this invention inwhich the bus bar insulator is provided with a removable portion whichserves to house the lugs for energizing the panelboard.

. FIGURE 14A is a side elevation of the panelboard of FIGURE 14-.

FIGURE 15 is a partial plan view of another embodiment of this inventionin which the panelboard is energized through a circuit breaker which isa multiphase unit of the type adapted to be mounted to the panelboard asa branch circuit protective device.

FIGURE 16 is a plan view of the base adapter for the mounting of a maincircuit breaker as in FIGURE 15.

FIGURE 16A is a cross-section taken through line 16A-16A of FIGURE 16looking in the direction of arrows 16A-16A.

FIGURE 17 is an elevation of the adapter of FIGURE 16 looking in thedirection of arrows 1'7--17 of FIG- URE 16.

are?

FIGURES 18A and 18B are a plan view and an elevation of a wire grip foruse as a load terminal when the circuit breaker is mounted for use as ageneral circuit breaker.

FIGURE 18C is a side elevation showing the connector of FIGURES 18A and18B mounted in operative rela-' tionship to a panelboard adapter.

FIGURE 18 is a side elevation showing the utilization of straps forconnecting the line terminals of higher current rated circuit breakersto the panelboard of FIG- URE 15.

FIGURE 19 is a plan view showing the components as in FIGURE 18.

FIGURE 20 is a partialside elevation of the embodiment of FIGURE 21.

FIGURE 21 is a plan View of a slightly modified adapter which mounts amultiphase circuit breaker.

FIGURE 22 is an end view of the adapter of FIG- URE 21 looking in thedirection of arrows 22-22 of FIGURE 21.

FIGURE 23 is a cross-section taken through line 23 23 of FIGURE 21looking in the direction of arrows 2323.

FIGURE 24 is a plan view of an extension to be added to an arm of theinsulator of FIGURE 6 for constructing a panelboard with additionalcircuit breaker locations.

FIGURE 25 is a side elevation of the insulator extension of FIGURE 24.

FIGURE 26 is a bottom View of the insulator extension of FIGURE 24.

FIGURE 27 is a cross-section taken through line 2i'27 of FIGURE 24looking in the direction of arrows27?;'7.

FIGURE 28 is an end view of the extension of FI URE '24 looking in thedirection of arrows of FIGURE 24. 7

Now referring to the figures. Panelboard'fiti of FI URE 1 includesmounting plate 31 which carries U-shaped insulator 35 (FIGURE 6), add oninsulators 53, 54 U- shaped bus bar 36 (FIGURE 9), bus bar 37 (FIGURE11), U-shaped bus bar 33 (FIGURE 10}, terminal extensions 39A, MB and39C and wire grip assemblies ltlB and 49C. It is noted that whereelements of like constructions are designated by the same referencenuarms of the U and define recesses for line terminal or H wire gripassemblies 49.

Insulator 35 is substantially hollow and having internal U-shaped ribs42, 43 which are generally parallel to the outer walls 44, 45 ofinsulator 35 thereby defining three substantially parallel U-sbapedslots as, 47, 4% which with threaded apertures 61 which are adapted toreceive screws for making electrical connections to circuit breatersOuter bus bar 33, shown in FI URES 10 and 16A, is of similar sheetconstruction as bus bar 36, The offsets of bus bar 33 positioned alongthe arms thereof for engagement by branch circuit breakers, aredesignated MC-57C while the offsets for connection to the energizingcircuit are designated 53C and 5%). Each of the latter group of offsetsis also provided with threaded apertures 6i. 7

The center bus bar 3'7 illustrated in FIGURES 11 and 11A is constructedof rod-like material with offsets formed by transverse deformedportions. The branch circuit connecting offsets of bus bar 37 aredesignated 543-573 while the single offset for line connection isdesignated 59B. However, this last offset is provided with two threadedapertures 61 while the offsets 54-8-5715 are each provided with a singlethreaded aperture or.

are open at the bottom of insulator 35. Theinner wall 45 is providedwith inwardly extending lugs 49 having notches 5b which receive screws51 for securement of insulator 35 and the elements mounted thereto tomounting plate 31. Straight insulator sections 53 and 5d are added tothe arms of U-shape insulator 35 at lines 9% and 97 to form extensionsof the arms. The construction and function of insulators 53, 54 willhereinafter be explained.

As seen in FIGURES 9 and 9A, inner bus bar as is of bus bar as. Offsets54A through 59A are also provided The upper edge of The current carryingcapacity of the panelboard is determined by the height H of bus bars and38 since the thickness T of these bus bars is maintained uniformregardless of circuit breaker current rating. In order to increase thecurrent carrying capability of the middle phase, U-shape bus bar 37, busbar 65' constructed of rod-like material, is connected in parallel withcenter bus bar 3? by bringing it into abutment therewith as It has beenfound advantageous shown in FIGURE to weld bus bar 65 to bus bar 37, asclearly seen in FIG- I RE 1, at points designated W as well as at otherintermediate points not indicated. The widths of bus bars 36 and 38, asseen in 3, are for a maximum capacity panelboard consistent with theconstruction of insulater Sealing wax E9 is inserted in the slots ofinsulator as below bus bars 315% and 36 to provide an insulating barrierbetween these bus bars and mounting plate 31. FIGURE 5 shows theheight'of the inner and outer busbars for the case where the capacity ofthe panelboard is approximately half that of FIGURE 3. Under thesecircumstances the inner and outer bus bars 364 and are approximatelyhalf the height of bus bars so and 38.

After assembly in the insulators, the offsets of bus bar 36 areoutwardly bent, the offsets of bus bar 33 are inwardly bent, and theoffsets of bus bar 3'7 are located forward of the main portion of busbar 37. As clearly seen in FIGURE 2 the offsets of all three bus bars36, 337 and 38 are positioned so that the forward surfaces thereof liein a single plane parallel to the plane of mounting plate 31 and areexposed at the front surface of insulator Ed. I i v The forward surfaceof insulator 35 is provided with apertures 65A, 66A, 68A and 69A throughwhich offsets 55A, 56A, 58A and 59A, respectively, extend. Insulatorapertures C, etc, ddC and 69C are provided for the passage of offsets55C, 56C, 553C and 59C, respectively; lnaddition the top surface ofinsulatorfld is provided with apertures 65B, 66B and 693 through whichportions of offsets 553, see and 9B,.respectively, extend. Inner bus bar36 is disposed within insulator slot 46 with the outward bending of theoffsets of bus bar providing mechanical securement of bus bar 36 toinsulator 35. Similarly outer bus bar 38 disposed Within slot 43 ismechanically secured to insulator 35 by inwardly bending the offsets ofbus bar 38. The mechanical position of center bus bar 37 is maintainedby appropriately shaping the walls of groove 47 and alsoby providinginsulators '72 (FIGURE 2) disposed within groove 4-? to space the centerbus bar orbus bars as the case may be from base plate 31.

Two screws 73 electrically and mechanically secure strap 39A to offsetsSSA and 9A. Similarly two screws 74 electrically and mechanically securestrap 398 to offset while two screws 75 mechanically and electricallysecure strap 35C to offsets 55C and 59C} Nut and bolt securing meansfasten connector assemblies 441A- 40C to the respective straps 39A-39C.Leg 76, for the mechanical securement and positioning of circuitbreakers mounted in panelboard 30, is positioned between the arms ofU-shape bus bars 36-38 and extends parallel to these arms.

Each of the insulator sections 53 and 54 are of substantially identicalconstruction the only differences being the locations of mechanicalsecuring lugs 53A and 54A, respectively, and the locations of aperturesthrough which the bus bar offsets extend. Insulator 54 is illustrated indetail in FIGURES 24 through 28. Insulator 54 is provided with internalgrooves 46A, 47A and 48A which are aligned with grooves 46, 47 and 43,respectively, of insulator forming extensions thereof. The forwardsurface of insulator 54 is provided with apertures 67A, 67B and 67Cwhich communicate with grooves 46A, 47A and 48A, respectively, so as toprovide passages through which offsets 57A, 57B and 57C, respectively,extend. In a similar manner insulator 53 is provided with internalgrooves forming extensions of grooves 46 through 48 of insulator 35 atthe end of the other arm of insulator 35. Additional insulators 53, 54may be added as required to increase the number of circuit breakermounting locations in a given panelboard and in the event thatadditional locations are desired it is merely necessary to increase thelengths of the bus bar arms.

The embodiment of FIGURE 14 differs from the embodiment of FIGURE 1 inthat the web of insulator 135 is much narrower than the web-of insulator35. This construction is provided so that there will be a removableterminal base 100 which carries assemblies 453A, 4013 and C. Screws 101,extending through clearance apertures in barriers 102, 103 of removablebase 1%, mechanically secure removable terminal base 1% to mountingplate 31. Extensions of barriers 162, 1d?) extend into grooves at theend of barriers 194, 105, respectively, of U-shape insulator 135 at theweb thereof and end barriers 166, 107 of base 1130 overlap the ends ofthe web of insulator 135.

By making terminal base removable greater flexi bility is provided inthe system. Specifically base 111%) may be removed and replaced by amain switch or circuit breaker interposed between the panelboard and itsenergizing source. FIGURE 15 shows three phase circuit breaker connectedto insulating base 135 and the current carrying elements associated withbase 135. Circuit breaker 110 is of the type disclosed in the aforesaidapplication Serial No. 285,681, filed June 5, 1963.

In FIGURE 15 base 100 has been replaced by adapter 115 shown in planview in FIGURE 16. Adapter 115 includes insulator 12%) provided withextensions 1 17 having slots 118 for mechanical securement of adapter115 to mounting plate 31 by fastening means 119 (FIG- URE l5). Insulator120 is formed as a closed loop provided with concentric closed loopslots open at the rear of insulator 120. Within the slots are disposedbus bars 136, 137 and 138 similar in construction to bus bar-s 36through 38, respectively. Bus bars 136 and 133 are each U-shaped memberswhile bus bar 137 is formed as a loop having an opening therein. Bus bar136 is provided with offsets 139A, 146A and 141A, bus bar 138 isprovided with offsets 139C, 14PC and 141C, while center bus bar 137 isprovided with oifsets 1393, 1463 and 141B.

Offsets 139A, 1393 and 139C are disposed with the threaded apertures 61thereof in a straight line parallel to one of the long legs of insulatorThe remaining offsets are positioned so that the threaded apertures 61thereof are aligned along the other long leg of insulator 120. Insulator12% is provided with barriers 145, 146 which are received by the notchesin the barriers 1M, 1115, respectively, of insulator 135. Rib 147, forthe mechanical securement of circuit breaker 110, is disposed within thecavity formed by insulator 121) and is positioned parallel to the longlegs of insulator 120 remote from the legs having offsets 139A, 1393 and139C. As seen in FIGURES l5 and 18 suitable straps 151, 152 connect thebus bars of adapter 115 to the bus bars mounted to base 135. The lineterminals of circuit breaker 118 are electrically connected to offsets139A, 139B and 139C through offset straps 153. Line connections are madedirectly to the load terminals of circuit breaker 110.

In the embodiment of FIGURE 20 adapter 115 has been eliminated andconnections are made from adapter 153 to strap 151, directly by means ofU-shape conductors 159 having insulating coverings 163. As clearly seenin FIGURE 20, the webs of conductors 159 pass beneath circuit breaker110. In FIGURE 18C circuit breaker 116 is shown mounted to rib 147 foruse as a general purpose breaker. In this embodiment the insulationcovered U-shaped conductor 159, instead of being connected at theirright ends 161 to strap 151, are pro vided with wire grips 162. Eachwire grip 162, as clearly seen in FIGURES 18A and 18B, is provided withclearance apertures 163 for the passage of screws 164 which secureconnector 162 to conductor 159. Connector 162 includes clamping screw165 mated to a threaded aperture positioned between clearance apertures163 and extending into cavity 166 which is enterable from the side ofmounting rib 147 remote from circuit breaker 116.

In the adapter 2% of FIGURES 21 through 23 loop in sulator 2&1 isprovided with two rather than three, slots to receive bus bars. One slotis provided for center bus bar which is formed as an open loop while theother slot is provided for bus bars 2% and 2&6. Thus, it is seen thatthe insulator 2131 may be considerably narrower than insulator 12%. Busbar we is of the same construction as bus bar 136 of FIGURE 16 while busbar 2116 is a mirror image of bus bar 2% and takes the place of bus bar138 of FIGURE 16. Insulator 261 is provided with an enlarged notch 21dat the bottom thereof to provide ventilation for circuit breaker 1111.

Thus, this invention provides a novel construction for a multiphasepanelboard. This construction specifically provides points forelectrical connections which are equally spaced by a distance whichpermits either single pole or multipole circuit breakers of a particularconstruction to be inserted indiscriminately at any position on eitherof two legs of the panelboard. This specific circuit breakerconstruction is one in which mechanical securement of the circuitbreaker is of a rib disposed between the portions of the panelboardconductors to which the branch circuit breakers make electricalconnection. 1

Although there has been described a preferred embodiment of this novelinvention, many variations and modifications will now be apparent tothose skilled in the art. Therefore, this invention is to be limited,not by the specific disclosure herein, but only by the appending claims.7

The embodiments of the invention in which an exclusive privilege orproperty is claimed are defined as follows:

1. A device of the class described comprising a mounting member having aplate-like portion, a plurality of bus bars, means mounting said busbars in insulating relationship to said mounting member forward ofplate-like portion, a first and a second of said bus bars each having amain portion and a plurality of offsets defining locations for makingelectrical connections to the respective bus bars, said offsets of saidfirst and said second bus bars having the surfaces thereof remote fromsaid plate-like portion positioned in a plane parallel to saidplate-like portion, said oifsets of said first bus bar projecting in afirst direction from the main portion of said first bus bar, saidoffsets of said second bus bar projecting in a second direction fromsaidmain portion of said second bus bar, said first direction beingdifferent than said second direction, a third of said plurality of saidbus bars positioned between said first and said second bus bars, saidthird bus bar having a main portion and a plurality of offsetsdefinenemas ing locations for making electrical connections thereto,

' said oilsets of said third bus bar having the surfaces thereof remotefrom said plate-like portion positioned in said plane, said first, saidsecond, and said third bus bars each formed as separate concentricloops, at first, a second and a third U-shaped bus bar insulatinglymounted from one another and from said mounting member, each of saidU-shaped bus bars having offsets defining locations for makingelectrical connections to said bus bars, said oiisets of said U-shapedbus bars being positioned with the surfaces thereof remote from saidplate-like portion in a plane parallel thereto, and means electricallyconnecting said first, said second, and said third loops to said first,said second, and said third bus bars, respectively, at the Webs thereof.

2. The device of claim it in which there is a first circuit breakermounting rib disposed midway between the arms oi the U-shaped bus bars,extending parallel to these arms, a second circuit breaker mounting ribsecured to said platelike portion and operativcly positioned within theloops.

3. A panelboard comprising: a mounting member having a plate-likeportion, a plurality of bus bars;

means mounting said bus bars in insulating relationship to said mountingmember forward of said plate-like portion;

a first and a second of said bus bars each having a' U-shaped mainportion and a plurality of offsets defining locations for makingelectrical connections to the respective bus bars, a third of saidplurality of bus bars positioned between said first and said second busbars, said third bus bar having a U-shaped main portion and a pluralityof offsets defining locations for making electrical connectionsthereto,said oitsets of said third bus bar projecting forward of saidmain portion of said third bus bar, said oilsets of said first, second,and third bus bars having the surfaces thereof remote from saidplate-like portion positioned in a plane parallel to said plate-likeportion, said oiisets of said first bus bar projecting in a firstdirection from the main portion of said first bus bar and in front oisaid third bus bar, said offsets of said second bus bars rojecting in anopposite direction from said main portion of said second bus bar and infront of said third bus bar, said first and said second bus bar mainportions being constructed of material having a cross-section in whichthe major dimension is many times greater than the minor dimension, theminor dimension of the third bus bar cross-section being greater thansaid minor dimensions of said first and said second bus bars, a circuitbreaker mounting rib positioned midway between the arms of the U-shapedbus bars and extending parallel thereto;

a first group of said otfsets arranged in a first line and a secondgroup of said offsets arranged in a second line, said first and saidsecond lines being parallel to said rib and equally spaced therefrom.

4. The device of claim 3 in which the ofisets in each of said lines arepositioned in a phased sequence arrangement.

5. The device of claim 3 in Whichthere is a terminal means connected tothe bus bars at the web of the U.

6. A panelboard comprising a mounting member having a plate-likeportion, a plurality of U-shaped bus bars, U-shaped means mounting saidbus bars in insulating relationship to said mounting member forward ofsaid platelike portion, said U-shaped means comprising a web portionandtwo extending arm portions,a first and second of said bus bars eachhaving a main portion and a plurality of offset connectingmembersdefining locations for making electrical connections to saidrespective bus bars, said offset connecting members of saidfirst andsecond bus bars having portions thereof remote from said platemembers ofsaid first bus bar projecting in a first direction from the main portionof one arm of said first U- shaped bus bar, said portions oi said offsetconnecting members or said second bus bar projecting in a seconddirection from said main portions of the other arm of said secondU-shaped bus her, said first direction being different than said seconddirection, a third U-shaped bus bar having a main portion and aplurality of offset connecting members defining locations for makingelectrical connections thereto, said offset connecting members of saidthird bus bar having a portion thereof remote from said plate-likeportion and positioned in said plane, said portions being capable ofbeing electrically connected to circuit breakers mounted between theextending arm portions of said U-shaped means. 7

7. The panelboard of claim 6 in which said portions of the oiisetconnecting members of said first, second, and said third bus bars areintended to be engaged by circuit breaker terminals and are positionedin a phased sequence arrangement. v,

d. The panelboard of claim 6 in which there is a circult realrermounting rib positioned midway between the arms of the U-shaped bus barsand extending parallel thereto. i

9. T e panelboard of claim it in which a first group of said portions ofsaid ofiset connecting members are arranged in a first line and a secondgroup of said portions of the offset connecting members are arranged ina second line, said'first and said second lines being parallel to saidrib and equally spaced therefrom a iii. A panelboard comprising amounting member having a plate-like portion, a plurality of bus bars,means including a looped insulator mounting said bus bars in insulatingrelationship to said mounting member forward of said plate-like portion,a first and a second of said bus bars each having a main portion and aplurality of offsets defining locations for making electricalconnections to=the respective bus bars, said oiisets of said first andsaid second bus bars having the surfaces thereof remote said plate-likeportion positioned in a plane parallel to said plate-like portion, saidofisets of said first bus bars projecting in a first direction from themain portion of said first bus bar, said olfsets of said second bus barprojecting in a second direction from the main portion of said secondbus bar, a thirdof said plurality of bus bars being formed as a loop,said loop being substantially rectangular, said third bus bar having amain portion anda plurality of oil-sets defining locations for makingelectrical connections thereto, said offsets of said third bus barhaving the surfaces thereof remote rmm said plate-like portion andpositioned in said plane, a circuitbreaker mounting rib secured to saidplate-like portion and being 'operably positioned within the loop of theinsulator, a

material having a cross-section in which the major dimcnsion is manytimes greater thanthe minor dimension, the minor dimension or" the thirdbus bar cross-section i being greater than the minor dimensions of saidfirst and ike portion and positioned in a plane parallel to said]plate-lil e portion; said portions of said offset connecting.

said second bus'bars.

References tCited by the Examiner UNITED STATES PATENTS 2,733,386 1/56Myer-s 3l7ll9 2,766,405 19/56 Edmunds 317-119 2,880,263 3/59 Herrmann eta1. 317-119 3,041,505 6/62 ronN F. BURNS, Primary mammal.

IGHN P. WILDMA'N, Examiner.

Norden '317.1l9 v

6. A PANELBOARD COMPRISING A MOUNTING MEMBER HAVING A PLATE-LIKEPORTION, A PLURALITY OF U-SHAPED BUS BARS, U-SHAPED MEANS MOUNTING SAIDBUS BARS IN INSULATING RELATIONSHIP TO SAID MOUNTING MEMBER FORWARD OFSAID PLATELIKE PORTION, SAID U-SHAPED MEANS COMPRISING A WEB PORTION ANDTWO EXTENDING ARM PORTIONS, A FIRST AND SECOND OF SAID BUS BARS EACHHAVING A MAIN PORTION AND A PLURALITY OF OFFSET CONNECTING MEMBERSDEFINING LOCATIONS FOR MAKING ELECTRICAL CONNECTIONS TO SAID RESPECTIVEBUS BARS, SAID OFFSET CONNECTING MEMBERS OF SAID FIRST AND SECOND BUSBARS HAVING PORTIONS THEREOF REMOTE FROM SAID PLATELIKE PORTION ANDPOSITION IN A PLANE PARALLEL TO SAID PLATE-LIKE PORTION; SAID PORTIONSOF SAID OFFSET CONNECTING MEMBERS OF SAID FIRST BUS BAR PROJECTING IN AFIRST DIRECTION FROM THE MAIN PORTION OF ONE ARM OF SAID FIRST U-